A. Field of the Invention
The present invention relates to efficient production of individualized labels, and more particularly to a method of producing such labels using spark-discharge recording techniques and constructions therefor.
B. Description of the Related Art
Current mass-production labelmaking methods are typically directed toward generating large numbers of identical labels at low unit cost. Examples of traditional methods include block or plate printing processes that utilize solvent- or water-based printing inks. Such methods are inherently inapplicable to applications requiring some degree of uniqueness to be imparted to each label, however, because reconfiguration of the printing apparatus is mechanically prohibitive.
Individualized labels, or labels containing a field within which one or more printed elements are varied, are gaining in importance with the emergence of low-cost optical and magnetic scanning devices. While manufacturers have long identified goods with unique serial numbers or other such markings, scanning equipment permits rapid and automatic retrieval of a variety of information associated with a particular item, such as date of manufacture, origin and current price. Such information, or portions thereof, may apply only to a single item or group of items, and can also be subject to change. Its ready availability greatly simplifies inventory control, transportation and cashier operations.
Readily accessible sources of information about particular individuals have also become necessary, as transactions that have heretofore required written instruments now are amenable to electronic execution. Credit, banking and identification information may be encoded on magnetic media that an individual can conveniently carry and present to a scanning device, permitting convenient financial dealings and credit approval.
We are aware of few techniques expressly developed for large-scale production of individualized labels, although some known technologies might be adaptable to this purpose. For example, U.S. Pat. No. 4,638,340 discloses a two-color thermosensitive recording label capable of forming two different colors when heated at different temperatures. U.S. Pat. No. 4,577,205 discloses labels comprising an ink layer curable by electron-beam emission and a thermosensitive color-forming layer. Both types of labels appear capable of production using high-speed, computer-controlled imaging equipment However, both involve chemical reactions for imaging, and typical thermosensitive recording apparatus require contact between a recording stylus and the thermosensitive material.
The present invention utilizes non-contacting spark-discharge recording apparatus, such as that described in U.S. Pat. No. 4,911,075 (commonly owned with the present application and hereby incorporated by reference); copending application Ser. Nos. 07/413,172, filed 09/27/89, U.S. Pat. No. 5,005,479 and 07/554,089, filed 07/17/90 (commonly owned with the present application and hereby incorporated by reference); and a PCT application filed in the U.S. Patent and Trademark Office on Sept. 28, 1990 entitled "Plasma-Jet Imaging Apparatus and Method" and assigned Ser. No. US90/05546 (also commonly owned with the present application and hereby incorporated by reference). This type of imaging system offers speed, precision and amenability to computer control. It has been applied to lithographic and mask printing, where a single plate is used repeatably to print multiple copies of the same image, but not, as far as we are aware, to direct production of finished articles.